This invention is directed to a method and apparatus for manufacturing of yarn from natural- and synthetic fibres, using a pneumatic spinning technique.
Prior art equipment and methods for pneumatic manufacturing of yarn with fibres having been entrained by air introduced into a non-rotational spinning chamber, form a ring caused by the air jets to whirling over the chamber inner walls, within a plane perpendicular to the chamber center line. Accordingly, the yarn becomes formed and twisted by gathering of fibres from the whirling ring, and finally discharged out of the chamber.
At the vacuum source side, the chamber is provided with the peripheral tangent ducts to supply air, and a fibre delivery channel, the latter being located in the chamber upper part, above the outlet of the yarn discharge channel.
In operation, the spinning rate is proportional to the peripheral velocities in the zone where the fibre ring is being formed, in the spinning section. The field of the peripheral velocities as it is being formed is counteracted by the whirl core being generated in the chamber center line, where rotational field intensification takes place. The powerful whirl core adversely affects the velocity field distribution, thus preventing the formation of a velocity distribution that is correct, since a distinct maximum occurs at the chamber walls. With such a powerful whirl core, the peripheral velocity field distributions display the velocity maximum shifted towards the chamber center, in direction of smaller radii. Such being the case, the formation of the peripheral velocities at the chamber walls appears impracticable.